A body-worn camera that is mounted on, for example, the shoulder of a person has been used. For example, a security guard stands guard while wearing the body-worn camera. Therefore, the guard can remotely monitor a video captured by the body-worn camera or can analyze the video while standing guard in a spot.
A technique for making it easy to use a body-worn camera has been developed. For example, Patent Document 1 discloses a technique that easily adjusts the position of a glasses-type head-mounted display. The head-mounted display disclosed in Patent Document 1 is fixed to the head of the user by a fixing portion that presses both regions of the head of the user with appropriate force and an arm that extends from the frontal region of the head to the top of the head. A display corresponding to a lens portion of the glasses is connected to the arm by a rotating mechanism unit. The user can use the rotation mechanism unit to move up or down the display in a state in which the fixing portion and the arm are fixed to the head of the user.
The head-mounted display disclosed in Patent Document 1 is provided with three cameras. First, two cameras are provided at the sides of the display. In addition, one camera is provided at the top of the head of the arm.
As described above, since the display is movable, the display is moved to change the fields of view of the cameras provided in the display. In contrast, since the position of the camera provided at the top of the head is fixed, the field of view of the camera is fixed. Therefore, the head-mounted display disclosed in Patent Document 1 compares an image that is generated by the camera fixed to the top of the head with an image that is generated by the camera provided in the display to determine whether the display is located at a predetermined position.